1. Field of the Invention
This invention relates, in general, to containers for holding photographic film and, more specifically, to containers for holding photographic film that are impervious to electromagnetic radiation and moisture.
2. Description of the Prior Art
It is a daily occurrence in major airports throughout the world for carry-on luggage to be scanned by X-rays so as to determine the contents of luggage in an effort to discourage hijacking of airplanes. However, photographic film and electronic equipment containing transistors are sensitive to such X-ray radiation and are commonly damaged or destroyed by the well-intentioned X-ray search.
As is well known, radiation resistant materials, such as lead, may be interposed between a source of radiation and an object to protect the object from the damaging effects of such radiation. There has also been developed in the prior art various types of leadlined containers to protect photographic film and other radiation sensitive objects from the damaging effects of radiation.
Thus, in U.S. Pat. No. 3,793,528, the gadget bag for a camera includes a space therein for accommodating the camera and film. The space is surrounded by a layer of thermal insulating material and a thin layer of an X-ray resistant material, such as lead, to protect the camera and film from the damaging effects of heat and radiation.
In U.S. Pat. No. 3,845,316, a radiation resistant container is fabricated from laminated sheets of plastic and a radiation impervious material. In the preferred embodiment, the container is fabricated by folding sheets such that the ends are enclosed with at least an overlapping and an abutting inch of the radiation impervious material. The container is held closed by conventional wire bands clasped around the overlapped ends.
Although such radiation resistant containers for holding photographic film and the like provide some degree of radiation protection, they still allow entry of radiation, when abnormal amounts of radiation are produced by improperly set-up or operated baggage search equipment, into the container which causes damage to the film. Since the amount of X-ray output from such baggage search equipment varies substantially from airport to airport, the above-mentioned film containers are ineffective in providing a container that protects photographic film from radiation damage in all situations. Also such film containers possess deficiencies in other areas that further restrict or limit their usefulness.
For one, such devices typically use lead foil, on the order of one to two mils thick, as the radiation resistant material. Such a thin layer affords protection for only small amounts and a small range of wave lengths of radiation, such as those associated with airport baggage check equipment that is properly operated within design parameters. Although it is possible to utilize greater thicknesses of the radiation resistant material such greater thicknesses result in a heavier, bulkier container that is difficult to conveniently carry by itself or in multiple numbers.
For another, such radiation resistant containers are pervious to gas and moisture, which can be just as damaging to film and other sensitive equipment as X-rays.
Since such containers are generally small, they are easily damaged since they are typically thrown in larger containers, such as camera gadget bags or suitcases. Thus, there is a distinct possibility for such containers and their valuable contents to be crushed or inadvertently opened under the vibrations and external forces exerted thereon.
Finally, such containers are offtimes exposed to extreme conditions of heat or cold that can also damage the contents of the container and, particularly, photographic film. Although it is known to provide some type of thermal insulation, as shown in U.S. Pat. No. 3,793,528, such usage of insulation in the prior art has resulted in bulky, difficult to seal containers.
Thus, it would be desirable to provide a film safe or container for protecting photographic film from the damaging effects of electromagnetic radiation which overcomes the problems of prior art radiation resistant containers. It would also be desirable to provide a film safe which, in addition to radiation protection, also protects the photographic film from other external environmental conditions, such as extreme heat and/or cold. It would also be desirable to provide a film safe that maintains the physical integrity of the film despite external forces that may be exerted on the film safe. Finally, it would be desirable to provide a film safe which is easily and quickly adapted to receive at least one standard sized roll of photographic film and, at the same time, which provides a sealable enclosure for the film that is resistant to inadvertant opening.